Color development process and compositions

ABSTRACT

An abbreviated process for the color development of photographic elements containing an aldehyde, the heating the element in an elevated temperature environment of at least 65*C. in the presence of certain gelatin permeable compounds until full color density is attained without degradation of the photographic element. Such gelatin permeable compounds incoude aromatic alcohols, their esters and ethers, alkylene glycols having at least 3 carbon atoms per molecule and surface active compounds. These gelatin permeable compounds may be included in any processing bath after the color developer.

United States Patent Newman et al. Sept. 3, 1974 [54] COLOR DEVELOPMENT PROCESS AND 3,241,966 3/1966 Heilmann et al 96/60 BF COMPOSITIONS 3,620,725 11/1971 Kosta 96/60 BF 3,667,950 6/1972 Amano et al. 96/60 BF [75] Inventors: Norman Newman; Richard S. Fisch,

both of Paul Mmn; Enrico Primary ExaminerRonald H. Smith Fuflanetto savona Italy Assistant Examiner-Richard L. Schilling 73 Assignee; Minnesota Mining and Attorney, Agent, or Firm-Alexander, Sell, Steldt &

Manufacturing Company, St. Paul, DeLaHunt Minn' 57 ABSTRACT [22] Ffled' 1972 An abbreviated process for the color development of PP 309,116 photographic elements containing an aldehyde, the

heating the element in an elevated temperature envi- 52 U.S. c1. 96/55, 96/60 BF mmem at least in the Preseme 51 Int. Cl G03C 7/00, 0036 5/32 gelatin. Permeable until full F 58 Field Of Search 96/60 BF, 60 R, 55, 51, is tamed the phmqgraphc (36/111 R element. Such gelatm permeable compounds 1ncoude aromatic alcohols, their esters and ethers, alkylene [56] keferences'cited glycols thaving at least 3 catr lborigitoms per molecule and sur ace active compoun 5. ese ge atin permea- UNITED STATES PATENTS ble compounds may be included in any processing Johnson R after the olor developen 3,189,452 6/l965 Bard et al. 96/60 R 3,232,764 2/1966 Allen et al. 96/111 8 Claims, N0 Drawings COLOR DEVELOPMENT PROCESS AND COMPOSITIONS This invention relates to the processing of color photographic materials and especially to an abbreviated sequence for the processing of coupler-incorporated, color forming photographic films and prints.

One traditional method for processing exposed multilayer coupler incorporated photographic color materials, such as color print paper, uses several baths in the following sequence color developer, stop fix, silver bleach, a second fix, and a stabilizer bath with optional intervening wash steps. In this process the color developing agent (e.g., a paraphenylene diamine) reacts with color forming compounds in the presence of exposed silver halide. In a typical sequence for the development of a color paper or positive process, the steps may consist of a color developer, short stop, silver bleach, silver halide fix and stabilizer, normally with intervening wash steps. For a color negative process the sequence may consist of a prehardener, neutralizer, color developer, short stop, hardener, silver bleach, silver fix and stabilizer. Although it has often been assumed that the visible dye image is fully available at the end of the color development step, this has not been universally true. Frequently the colored image is only incompletely developed during the color development step and continues to visibly intensify during subsequent steps in the process.

Recently attempts have been made to simplify color processing by combining or eliminating certain of the baths, thereby providing a shorter processing sequence and, in certain instances, reducing or eliminating the disposal and potential pollution problem with spent baths. It has been known that the silver bleach and silver fix steps can be combined into a single bath which contains both a silver halide solvent and an oxidizing agent for silver. An illustrative bleach-fix (or blix" bath includes the iron complex of ethylene diamine tetraacetic acid and a thiosulphate. The need for a short stop and/or washes between the color developer and the bleach-fix baths can eliminated. Unfortunately, if the exposed photographic elements contain aldehyde hardening agents or aldehyde releasing hardening agents, the use of combined bleach-fix baths tends to result in incomplete dye formation. As indicated in U.S. Pat. No. 3,189,452, the inclusion of a ferricyanide bleach bath after the bleach-fix obviates the problem only by introducing another step involving a bath which raises serious disposal problems. It has been reported in the literature (see French Pat. No. 2,010,661) that color processes using bleach-fix baths immediately after development are desirably used for treating only those photographic materials which are essentially free of aldehydes (e.g., formaldehyde) or aldehyde releasing agents, since the presence of aldehyde tends to inhibit conversion of the leuco dye to its visible normal form.

One object of the present invention is to provide a method to obtain the'complete formation of the visible image in an abbreviated process making use of a bleach-fix bath after the color development step. Still another object of this invention is to provide an abbreviated color developing process which utilizes a bleachfix step which is capable of processing colored materials containing aldehyde'or aldehyde releasing materials.

These and other objects of this invention are realized by treating an exposed color-forming photographic element containing aldehyde or aldehyde releasing material and color couplers which react with a primary aromatic amine to form a visible dye, in an abbreviated processing sequence including a color development with a primary aromatic amine, an optional wash and a subsequent bleach-fix containing a silver halide solvent and an oxidizing agent for silver, the sequence being characterized by a step of heating the photographic element after color development either in an elevated temperature environment above the normal drying temperature, i.e. at least C., preferably at least C., until full color density is attained without degradation of the photographic element or in a temperature environment of at least 65C. in the presence of certain gelatin permeable additives until full color density is attained without degradation of the photo graphic element. The actual temperature and time of the heating step can be varied widely depending on the particular construction of the photographic element. For example, plastic film base should be processed in a time-temperature relationship to avoid excess curling or cracking of the film base, while glass photographic plates are, of course, not subject to this problem. When using temperatures of at least 90C., particularly above C, during the heating step, the heat is generally applied for from 30 seconds to about 10 minutes, preferably from 2 to 5 minutes, using any heating means, e.g. oven, hot roll, radiant heater, radio frequency drier, etc. The heating of the photographic element may be conducted during the optional wash step following color development or at any subsequent point in the processing up to and including the final drying or even as a post drying step. The element may be either wet or dry when the heat treatment occurs. Generally drying with heat at above normal drying temperatures is the most convenient method to achieve the desired results without need for an additional step.

It has been found that the time and/or temperature of the heating step can be reduced if certain gelatin permeable additives are present in the gelatin emulsion layer or layers of the photographic element during this heating step. They may be added to the optional wash following color development or to any of the subsequent baths but are preferably dissolved in the bath just preceding the heat step, in a concentration above 5 grams per liter, preferably above 10 grams per liter and up to as much as 50 grams per liter. The additives may be conveniently included in the stabilizer bath or may be contained in the bleach-fix bath even if the stabilizer and bleach-fix baths are combined as described in British Pat. No. 1,190,855. Although some of these additives have been used in color processing baths for various purposes (e.g., see U.S. Pat. No. 3,241,966 and German Pat. 966,410), they have been used only in relatively low concentration levels as compared to their use in the present invention. They are either water soluble or soluble in water in the presence of a cosolvent, such as ethylene glycol). The useful additives of this invention are gelatin permeable compounds in the following categories:

I Aromatic alcohols and their esters and ethers, having no more than 20 carbon atoms per molecule and having the formula Where It and p or 1; Z and Y are hydrogen or an aliphatic, arylaliphatic or aromatic radical having no more than 8 carbon atoms; and X is an aromatic radical. The preferred esters or carboxy esters, and the aromatic radicals are preferably phenyl radicals (including substituted phenyl II Alkylene glycols having at least 3 carbon atoms per molecule and having the formula Where m is 1 to 25, X is hydrogen or methyl, and Y is hydrogen or an alkyl group with up to 10 carbon atoms.

Ill The additive may also be a surface active compound, which as used herein is defined by the following test procedure.

Test T-l. Into a 23 X 85 mm vial is placed 10 ml of cyclohexane and 10 ml of a 1% by weight aqueous solution of the test compound. The vial is then shaken vigorously for 25 complete cycles, allowed to settle for 5 to minutes, and the contents examined. Three resulting conditions are possible.

1. Two essentially clear phases, a cyclohexane upper layer and a lower water layer.

2. Three phases consisting of an upper cyclohexane layer, a lower water layer, and a significant visibly detectable intermediate layer which is an emulsion.

3. Either (a) a single emulsion phase or (b) a combination of one clear phase, either cyclohexane or water, and an emulsion phase.

If this test fails to produce condition 2 or 3 the test is repeated (Test T-2) using a 10% by weight aqueous solution of the test compound. If the repeat test fails to produce condition 2 or 3, the test is repeated (Test T-3) a third time using a 1% by weight solution of the 1-phenoxy-2-propanol in place of the cyclohexane solution. If either condition 2 or 3 is realized in any of the three tests, the test compound is a suitable surface active compound.

One simple test for determining whether any of the test compounds are gelatin permeable consists of immersing a gelatin emulsion coated element into an aqueous solution (2% by weight) of the test compound for minutes, withdrawing the element from the test solution, rinsing the surface thoroughly with water, immersing the gelatin element into a water bath for at least one hour, and measuring the surface tension of the water to determine if a change has occurred. Changes in the surface tension of the water indicate the elution of the test material from the gelatin if it previously had permeated the gelatin and if it is surface active. A sample of the same gelatin which has not been immersed in a test solution should be run simultaneously as a standard. If the material is not a surface active one, the elutriate can be analyzed for the presence of the test compound.

In the following examples the color developer bath was of the conventional type containing a primary aromatic amine color developer, a source of alkali and the usual preservatives and image enhancers. The photosensitive material was a multilayer construction containing blue sensitive silver halide emulsion containing the open chain ketomethylene yellow dye forming coupler, green sensitive silver emulsion containing the 5- pyrazolone magenta dye-forming coupler, and red sensitized silver halide emulsion containing the phenolic cyan dye-forming coupler. The photosensitive element also contained formaldehyde hardening agent.

Example 1 A sample of photosensitive material (color print paper) of the type described above was exposed using a sensitometer capable of recording a latent image of both selective color and gray scale patches and was processed in the conventional sequence of color developer, bleach-fix, wash and dry. A sample of the material was run through this process using a bleach-fix of the following composition:

iron-ethylenediaminetetraacetic acid complex 40 grams sodium salt of ethylenediaminetetraacetic 15 grams sodium sulfite 5 grams ammonium thiosulfate of a 60 percent aqueous solution ml A second sample was processed in the same sequence, the bleach-fix bath being of the same composition except for the addition of 20 grams/liter of polyoxyethylenecocoamine (ETHOMEEN C/20, a trademarked product of Armour and Company).

Samples of the materials processed in both of the above procedures were dried for 7 minutes in a 150F. environment and the resulting magenta selective densities were measured with a color densitometer. The magenta density of the sample processed through the bleach-fix bath containing the polyoxyethylenecocoamine surface active additive was 1.98 as compared with a magenta density of 1.33 for the sample processed in the bleach-fix bath without the additive.

Example 2 Special Bath A ethylene glycol I00 ml/liter benzyl alcohol 20 ml/liter propylene glycol phenyl ether 10 ml/liter (the remainder being water) Both the benzyl alcohol and the propylene glycol phenyl ether are additives within the scope of this invention.

Special Bath B This bath contained only water as a control for Special Bath A.

Special Bath C citric acid monohydrate 7.00 gm/liter potassium hydroxide to adjust pH to 4.8

formaldehyde (37% formalin) 0.185 gm/liter benzoic acid .33 gm/liter triethylene glycol 25 ml/liter benzyl alcohol 20 ml/liter propylene glycol phenyl ether 10 ml/liter The last 3 ingredients are additives within the scope of this invention. This special bath is a stabilizer bath with the inclusion of the gelatin permeable additives.

Special Bath D Sample through Special Bath Magenta Density A 2.10 B 1.50 C 1.98 D 1.53

Example 3 The same photosensitive material used in Example 1 was exposed and then developed in the processing sequence color developer, bleach-fix, wash, stabilizer, wash, special bath and dry. The bleach-fix bath contained iron-ethylenediaminetetraacetic acid 40 grams complex sodium salt of ethylenediaminetetraacetic grams acid sodium sulfite 5 grams ammonium thiosulfatein 60% aqueous solution 150 ml The stabilizer bath had the same formulation as in Example 2-D. Two special baths were prepared. Bath A contained a 2 weight percent aqueous solution of Stearyl Chloride (ETHOQUAD 18/25, a trademarked product of Armour and Company) Special Bath B contained 2 weight percent aqueous solution of Examples run through the above processes were dried for 7 minutes in a 150F. environment. The samples processed in Special Bath A had a magenta density of 2.03, and the samples processed through Special Bath B had a magenta density of 1.65. A third sample, processed in the same manner but without any special bath, had a magenta dye density of 1.34. Example 4. The same photosensitive material used in Example 1 was exposed and then developed in the processing sequence color developer, bleach-fix, wash, stabilizer and dry. The bleach-fix was the same as that of Example 1, without a gelatin permeable additive, and the stabilizer was identical to that in Example 2-D. The drying was conducted under conventional drying conditions for color print paper, using a drying temperature of about 150F. for about 7 minutes. After the drying step the Elevated Drying Temperature Magenta Density C. 1.88 C. 2.10 l 10C. 2.10

Total magenta density was not realized until an elevated drying temperature of 90C. was used. The magenta density achieved prior to the elevated temperature step was 1.38. Similar results were achieved in a processing sequence in which the stabilizer bath was omitted entirely.

Illustrative gelatin permeable additives of this invention include benzyl alcohol, propylene glycol phenyl ether, phenyl glycol ether, diethylene glycol, triethylene glycol, polyoxyethylenes (e.g., Carbowax, a trademarked product of Union Carbide Co.), propylene glycol, dipropylene glycol, polyalkylene glycol ethers, methyl-bis-(2 hydroxyethyl) oleyl ammonium chloride, methyl-bis-(2-hydroxyethyl) octadecyl ammonium chloride, N-methyl-N-oleyl taurate (Na), N-cyclohexyl-N-palmitoyl taurate (Na), lauryl betaine, cetyl ammonium sulfonic acid betaine, sodium lauryl sulfate, polyoxyethylated vegetable oil, polyoxyethylated fatty alcohol, sodium alkyl sulfonates, condensation products of ethoxide and a hydrophobic base formed by condensing propylene oxide and propylene glycol (e.g., Pluronic compounds, a trademarked product of Wyandotte Chemical Corp.), propylene glycol isobutyl ether (e.g., Dowanol PIB-T, a trademarked product of Dow Chemical Co. and the followmg:

Q-omcmon n-CsH1a(0 CHzCHzMOH n-CaHnO 0112011203 cmso OzNH4 H 0 01120112 15N cHmte ry chlon'de (EH 0 CHOH O H OHzOCHCHzOH 11-C7H15002Na C HnOSOsNa om-Q-son: n-C12H25Q a O. mg @oomomon SOaNa (e.g. "Triton X-102, a trademarked product of Rohm ti; Hass) H (O CH CH2)5-15SC12H25(t9fl5.) (e.g. N onic 218, a trademarked product of Permsalt Chemical) What is claimed is:

1. A process for processing an exposed color-forming silver halide photographic element containing aldehyde or aldehyde releasing materials and a color coupler which reacts with a primary aromatic amine developer to form a visible dye in a processing sequence comprising the steps of primary aromatic amine color development, an optional wash, a bleach-fix containing a silver halide solvent and an oxidizing agent for silver, and drying, the process being further characterized by heating the photographic element after the color development in an elevated temperature of at least 65C. until full color density is attained without degradation of the photographic element, in the presence of at least one gelatin permeable compound selected from the group consisting of l. aromatic alcohols, their esters and ethers, having no more than 20 carbon atoms per molecule and having the formula where n and p are independently 0 or 1; Z and Y are hydrogen or an aliphatic, arylaliphatic or aromatic radical having no more than 8 carbon atoms; and X is an aromatic radical.

2. alkylene glycols having at least 3 carbon atoms per molecule and having the formula where m is an integer from 1 to 25, X is hydrogen or methyl, and Y is hydrogen or an alkyl group with up to 10 carbon atoms, or

3. a surface active compound.

2. The process of claim 1 in which the heating step is carried out simultaneously with final drying of the photographic element.

3. The process of claim 1 in which the heating step is carried out after the bleach-fix step.

4. The process of claim 1 in which the heating step is carried out after a stabilizing step following the bleach-fix step.

5. The process of claim 1 in which the gelatin permeable compound is included in a bath subsequent to color development.

6. The process of claim 1 in which the gelatin permeable compound is included in the bath for the bleachfix step.

7. The process of claim 1 in which the gelatin permeable compound is included in a bath immediately prior to drying.

8. The process of claim 1 in which the gelatin permeable compound is included in a bath just prior to said heating in an elevated temperature environment of at least 65C. 

2. The process of claim 1 in which the heating step is carried out simultaneously with final drying of the photographic element.
 2. alkylene glycols having at least 3 carbon atoms per molecule and having the formula
 3. a surface active compound.
 3. The process of claim 1 in which the heating step is carried out after the bleach-fix step.
 4. The process of claim 1 in which the heating step is carried out after a stabilizing step following the bleach-fix step.
 5. The process of claim 1 in which the gelatin permeable compound is included in a bAth subsequent to color development.
 6. The process of claim 1 in which the gelatin permeable compound is included in the bath for the bleach-fix step.
 7. The process of claim 1 in which the gelatin permeable compound is included in a bath immediately prior to drying.
 8. The process of claim 1 in which the gelatin permeable compound is included in a bath just prior to said heating in an elevated temperature environment of at least 65*C. 